I have a big problem.... and need help from your experience/knowledge.

I previously install and use FREEBSD 7.0 release on my storage/backup
file server, for some reason, I can not transfer any files that is bigger
than 1GB. If I transfer it to Freebsd file server, the system complain
a kernel panic and reboot itself. So, I then waited and finally try
the new FreeBSD 7.1 release 2 days ago and test out with
transfer a file larger than 1GB, well, the system just freeze so I have
to reboot the system.
So does anyone know what is going on? Is there a limit size on for
transfer large file? What can I do to resolve this? FreeBSD is my file
server and backup and if I can not transfer large file guess I have to
change to UBUNTU and hope that it will not have the same problem.